Environmental Data Analysis and Visualization

Failing Gloriously

Warm-up exercise

On Canvas, there is a link to a survey for the ENVS Society. Please take a few moments to fill this out.

Visualization Critique

NY Times

Visualization Critique

Sandrine Henry/Tableau

Visualization Critique

Some things I heard last night

  • Is it OK if I don’t have a significant relationship?
  • Do I need to revise my project if I can’t answer my question with the data?
  • What if my results don’t show anything exciting/interesting?

Science

Science fails

Science fails all

Science fails all the

Science fails all the time

Science fails all the time.

Science fails all the time.

And that’s OK.

Does this mean I asked a bad question?

Does this mean I asked a bad question?

No.

Does this mean I asked a bad question?

No. Developing research questions takes time and practice. But they should never be asked with the expressed aim of getting a “significant” result.

Perverse incentives

Edwards and Roy 2017 Academic Research in the 21st Century DOI: 10.1089/ees.2016.0223

Fail productively

XKCD

  • A negative result is a result nonetheless.

  • If your assumptions/predictions didn’t work out, ask why not.

  • If your results are inconclusive, ask what data might be needed.

  • How does your result compare with other studies?

Fail productively, fail gloriously

 

“To fail productively, one has to be aware of the multiple contexts of that fail to find the valuable experience. To fail gloriously is to use the privileges that you have, as you are able, to make it safe for others to fail.” - Shawn Graham, Failing Gloriously

Reporting the results of a statistical test

When reporting the results of a statistical test, be sure to include the following information at a minimum within the context of the hypothesis:

  • Name of test and variable(s)

  • Test statistic(s) (letter will vary)

  • Degrees of freedom (df)

  • P-value (p)

Reporting the results of a statistical test


    Welch Two Sample t-test

data:  body_mass_g by species
t = -20.628, df = 170.4, p-value < 2.2e-16
alternative hypothesis: true difference in means between group Chinstrap and group Gentoo is not equal to 0
95 percent confidence interval:
 -1471.440 -1214.416
sample estimates:
mean in group Chinstrap    mean in group Gentoo 
               3733.088                5076.016

Reporting the results of a statistical test


“I used Welch’s two-sample t-test of the body masses for Gentoo and Chinstrap penguins, and rejected the null hypothesis that there is no difference in mean body mass between these two groups (t=-20.62, df=170.4, p<2.2e-16).”

Image file formats

Jif / Giphy

Image file formats

There are two main types of image formats

  • Bitmap (also known as raster)

  • Vector

Bitmap vs Vector

Wilke, C. 2019. Fundamentals of Data Visualization

Bitmap vs Vector

Wilke, C. 2019. Fundamentals of Data Visualization

Bitmap vs Vector

Bitmap

  • Sharpness depends on resolution and size

  • Consistent appearance across platforms

  • Best for complex images (photos, large numbers of elements)

Vector

  • Sharpness is scale-independent

  • Can look differently using different programs

  • Best for simple images (line drawings, simple graphs)

Image file formats

File Extension Type Use For
.jpg Bitmap Photos
.png Bitmap Line Drawings
.tif Bitmap Print
.svg Vector Line drawings (online)
.pdf Vector General purpose

Next week

  • Tuesday: Final lecture

  • Wednesday: Final final project development session

  • Thursday: SUBMIT POSTERS BY NOON, present at 4:30 PM